Ciprofloxacin (CIP) is frequently detected in agricultural soils and can be accumulated by crops, causing phytotoxicities and food safety concerns. However, the molecular basis of its phytotoxicity and phytoaccumulation is hardly known. Here, we analyzed physiological and molecular responses of choysum () to CIP stress by comparing low CIP accumulation variety (LAV) and high accumulation variety (HAV). Results showed that the LAV suffered more severe inhibition of growth and photosynthesis than the HAV, exhibiting a lower tolerance to CIP toxicity. Integrated transcriptome and proteome analyses suggested that more differentially expressed genes/proteins (DEGs/DEPs) involved in basic metabolic processes were downregulated to a larger extent in the LAV, explaining its lower CIP tolerance at molecular level. By contrast, more DEGs/DEPs involved in defense responses were upregulated to a larger extent in the HAV, showing the molecular basis of its stronger CIP tolerance. Further, a CIP phytotoxicity-responsive molecular network was constructed for the two varieties to better understand the molecular mechanisms underlying the variety-specific CIP tolerance and accumulation. The results present the first comprehensive molecular profile of plant response to CIP stress for molecular-assisted breeding to improve CIP tolerance and minimize CIP accumulation in crops.

中文翻译：

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深入了解环丙沙星植物毒性和植物积累的分子网络

环丙沙星 (CIP) 经常在农业土壤中检测到，并且可以在农作物中积累，引起植物毒性和食品安全问题。然而，其植物毒性和植物积累的分子基础却鲜为人知。在这里，我们通过比较低 CIP 积累品种 (LAV) 和高积累品种 (HAV) 分析了 choysum () 对 CIP 胁迫的生理和分子反应。结果表明，LAV 的生长和光合作用受到比 HAV 更严重的抑制，对 CIP 毒性的耐受性较低。综合转录组和蛋白质组分析表明，参与基本代谢过程的更多差异表达基因/蛋白质（DEG/DEP）在LAV中更大程度地下调，这解释了其在分子水平上较低的CIP耐受性。相比之下，更多参与防御反应的DEG/DEP在HAV中更大程度上调，显示出其更强的CIP耐受性的分子基础。此外，为这两个品种构建了 CIP 植物毒性响应分子网络，以更好地了解品种特异性 CIP 耐受和积累的分子机制。研究结果首次展示了植物对 CIP 胁迫反应的全面分子谱，可用于分子辅助育种，以提高 CIP 耐受性并最大限度地减少作物中的 CIP 积累。